the external **notmuch-<subcommand>** in ${PATH} instead. This allows
users to have their own notmuch related tools to be run via the
notmuch command. By design, this does not allow notmuch's own commands
-to be overriden using external commands.
+to be overridden using external commands.
+
+OPTION SYNTAX
+-------------
+
+All options accepting an argument can be used with '=' or ':' as a
+separator. For the cases where it's not ambiguous (in particular
+excluding boolean options), a space can also be used. The following
+are all equivalent:
+
+::
+
+ notmuch --config=alt-config config get user.name
+ notmuch --config:alt-config config get user.name
+ notmuch --config alt-config config get user.name
ENVIRONMENT
===========